sctp: Make the proc files per network namespace.

- Convert all of the files under /proc/net/sctp to be per
  network namespace.

- Don't print anything for /proc/net/sctp/snmp except in
  the initial network namespaces as the snmp counters still
  have to be converted to be per network namespace.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netns/sctp.h

@@ -2,8 +2,13 @@
 #define __NETNS_SCTP_H__
 
 struct sock;
+struct proc_dir_entry;
 
 struct netns_sctp {
+#ifdef CONFIG_PROC_FS
+	struct proc_dir_entry *proc_net_sctp;
+#endif
+
 	/* This is the global socket data structure used for responding to
 	 * the Out-of-the-blue (OOTB) packets.  A control sock will be created
 	 * for this socket at the initialization time.